1. Field of the Invention
The present invention relates to a reference coordinate calculating method, a reference coordinate calculating program, a recording medium thereof, a reference plate and a form measuring machine. In particular, the present invention relates to a reference coordinate calculating method or the like for obtaining a position (coordinates) of each of reference points provided on a large area as a coordinate point on a standardized reference coordinate system.
2. Description of Related Art
Conventionally, the form of a workpiece (an object to be measured) is measured by a coordinate measuring machine. However, a measurement area is limited within a platform of the coordinate measuring machine, and consequently the measurable size of the workpiece is limited.
In order to extend the measurement area, for instance, a method disclosed in Reference (JP11-6728A) has been known.
In this method, a movable measuring machine and a plurality of reference points of which coordinate values have already been obtained are prepared. Then, the form of the workpiece is measured by the movable measuring machine while the movable measuring machine is moved corresponding to a portion to be measured of the workpiece. Besides, a position of the movable measuring machine is obtained based on the measurement results of the respective reference points. The entire form of the workpiece can be obtained by combining measurement data obtained when the workpiece is measured by the measuring machine with the position of the measuring machine in each measurement timing.
However, when groups of the reference points are set for obtaining the position of the movable measuring machine, the coordinates of the respective reference points have been measured and registered by the measuring machine (the coordinate measuring machine) including all of the reference points within the measurement area. Therefore, the measuring machine had to be extremely large. It is difficult to prepare such large measuring machine, requiring enormous cost as well as a large space for installing the measuring machine, for example, as a typical plant facility.